Walking
Walking is the simplest form of exercise. It is healthy and it can actually increase your life span.
A moderate level of physical activity, such as walking 30 minutes a day, lengthened life by 1.3 years and added 1.1 more years without cardiovascular disease, compared with those with low activity levels. Those who chose a high physical activity level gained 3.7 years of life and added 3.3 more years without cardiovascular disease.
source:http://walking.about.com/
Don’t wait for the disease to develop before you start working out for your health. Prevention is still better than cure. You do not really need to spend a special time just to walk. You can do it with your daily routine or habits. Instead of taking the elevator, take the stairs. There’s no need to ride a car in going to places where you can walk the distance. There are a lot of ways on how you can get yourself walking. All you need to do is to start putting it in your mind that you must take a walk more often.